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W McFarland

Publications and source records attributed to W McFarland.

At least 19 recordsLinked to original sources
PubMed2006

Human immunodeficiency virus test-seeking motivation in blood donors, São Paulo, Brazil.

BACKGROUND AND OBJECTIVE: Previous studies have shown that volunteer, community-recruited donors have a higher prevalence of human immunodeficiency virus (HIV) infection in São Paulo, Brazil, than replacement donors. One hypothesis which may explain this unexpected finding is that some individuals donate blood because they are seeking HIV testing. The objective of this study was to characterize test-seeking blood donors and to determine whether they are at higher risk for HIV infection compared with other donors. MATERIALS AND METHODS: Subjects presenting for blood donation were asked to participate in a study assessing their motivations (including test seeking) to donate, as measured by perceiving donation as a means to obtain infectious disease test results. Participants completed the standard blood bank predonation screening questions plus our additional survey, and were tested for HIV, hepatitis B virus (HBV), hepatitis C virus (HCV), human T-cell lymphocytotrophic virus (HTLV) I/II, syphilis and Chagas' disease. As a result of anticipated low statistical power to directly measure the association between test-seeking motivation and HIV infection, we tested for herpes simplex virus type 2 (HSV-2) as a marker of sexual risk for HIV. Our survey includes accepted donors as well as persons whose risk-behaviour histories would result in their exclusion from donation according to routine screening procedures. RESULTS: Of 1,720 potential blood donors randomly selected and approached, 1,600 (93.0%) participated. Overall, 141 (8.8%) were classified as test seekers; 15.6% of these were HSV-2 positive. The proportion of test seekers was the same among community-recruited and replacement donors. Test seekers had a higher prevalence of HSV-2 [adjusted odds ratio (AOR) 1.66; 95% confidence interval (CI): 1.06-2.59] adjusting for age, gender and prior donation. The association was significant among community-recruited blood donors whose previous donation was more than 1 year ago (i.e. 'lapsed donors') (AOR 2.55; 95% CI: 1.20-5.44). Test seekers were not more likely to be rejected from blood donation as a result of health reasons, self-reported HIV risk-related behaviour, or by their own confidential unit exclusion. We found no difference in HSV-2 prevalence between persons accepted for donation (15.7%) and those rejected because of self-reported sexual risk (16.7%). CONCLUSIONS: We did not detect a difference in the proportion of test seekers across different types of blood donors; however, we did detect an association between HSV-2 infection and test seeking, especially among community-recruited lapsed blood donors. Of note, questions on test-seeking behaviour detected donors with increased prevalence of HSV-2, but the self-reported sexual risk behaviours currently used for deferral criteria did not. Incentives to get tested at sites other than blood banks may decrease the residual risk of HIV in the blood supply.

Adult↗
PubMed2006

Increases in sexually transmitted infections and sexual risk behaviour without a concurrent increase in HIV incidence among men who have sex with men in San Francisco: a suggestion of HIV serosorting?

BACKGROUND: Sexually transmitted infections (STI) and unprotected anal intercourse (UAI) have been increasing among men who have sex with men (MSM) in San Francisco. However, HIV incidence has stabilised. OBJECTIVES: To describe recent trends in sexual risk behaviour, STI, and HIV incidence among MSM in San Francisco and to assess whether increases in HIV serosorting (that is, selective unprotected sex with partners of the same HIV status) may contribute to preventing further expansion of the epidemic. METHODS: The study applies an ecological approach and follows the principles of second generation HIV surveillance. Temporal trends in biological and behavioural measures among MSM were assessed using multiple pre-existing DATA SOURCES: STI case reporting, prevention outreach programmatic data, and voluntary HIV counselling and testing data. RESULTS: Reported STI cases among MSM rose from 1998 through 2004, although the rate of increase slowed between 2002 and 2004. Rectal gonorrhoea cases increased from 157 to 389 while early syphilis increased from nine to 492. UAI increased overall from 1998 to 2004 (p<0.001) in community based surveys; however, UAI with partners of unknown HIV serostatus decreased overall (p<0.001) among HIV negative MSM, and among HIV positive MSM it declined from 30.7% in 2001 to a low of 21.0% in 2004 (p<0.001). Any UAI, receptive UAI, and insertive UAI with a known HIV positive partner decreased overall from 1998 to 2004 (p<0.001) among MSM seeking anonymous HIV testing and at the STI clinic testing programme. HIV incidence using the serological testing algorithm for recent HIV seroconversion (STARHS) peaked in 1999 at 4.1% at the anonymous testing sites and 4.8% at the STI clinic voluntary testing programme, with rates levelling off through 2004. CONCLUSIONS: HIV incidence among MSM appears to have stabilised at a plateau following several years of resurgence. Increases in the selection of sexual partners of concordant HIV serostatus may be contributing to the stabilisation of the epidemic. However, current incidence rates of STI and HIV remain high. Moreover, a strategy of risk reduction by HIV serosorting can be severely limited by imperfect knowledge of one's own and one's partners' serostatus.

Adult↗
PubMed2005

Health indicators among low income women who report a history of sex work: the population based Northern California Young Women's Survey.

OBJECTIVES: We examined differences in demographic characteristics, HIV related risk behaviour, prevalence of sexually transmitted infections (STI), and HIV and other health concerns among women with and without a history of sex work. METHODS: A secondary analysis of a population based, cross sectional survey of young, low income women in northern California. RESULTS: Of the 2543 women interviewed, 8.9% reported a history of sex work. These women reported more lifetime male sexual partners, were more likely to use drugs before sex, and were more likely to have a history of having sex with partners at high risk for HIV (that is, men who have sex with men, inject drugs, or were known to be HIV positive). They were significantly more likely to have positive serology for syphilis, herpes simplex virus type 2 (HSV-2), and hepatitis C regardless of their personal injecting drug use history; however, they were no more likely to have HIV, chlamydia, gonorrhoea, hepatitis A or hepatitis B infection compared to women without a history of sex work. Women with a history of sex work were significantly more likely to have a history of sexual coercion and tobacco use. CONCLUSIONS: These data measure the population prevalence of sex work among low income women and associated STI. Women with a history of sex work have health concerns beyond STI and HIV treatment and prevention.

Adolescent↗
PubMed2005

Malaria prevention practices in Mopti region, Mali.

OBJECTIVES: To assess insecticide-treated nets (ITNs) use, other malaria prevention measures, knowledge of malaria and diffusion of information about ITNs by the National Malaria Control Programme (NMCP) in Mali. DESIGN: A descriptive cross-sectional study. SETTING: Four villages in Mopti region, Mali that had participated in the Mopti Regional Malaria Control Program (MRMCP) ITN Education Programme five years prior. PARTICIPANTS: Three hundred thirty nine randomly-selected households. Within each household, mothers of children one to nine years of age were interviewed regarding knowledge of malaria and prevention practices. RESULTS: Overall, 11% of households used ITNs, with 97% of these in two villages. Ninety eight percent of households used bednets, 22% used insecticide sprays and 39% used mosquito coils. Significant predictors of ITNs use were: head of household literacy, larger family size, Bambara ethnicity, hearing about the NMCP and hearing about ITNs from health agents. Reasons why ITNs were not used included not knowing anything about ITNs, cost and not having net impregnation services readily available in the village. Levels of knowledge concerning malaria disease, transmission and prevention varied amongst the four villages. ITN households had significantly higher levels of knowledge about malaria and its prevention. CONCLUSION: Five years after the implementation of the MRMCP, ITNs use was low and diffusion of malaria prevention information was unequal among villages. Future efforts in improving the programme must recognise these differences in knowledge and ITNs utilisation and make village-specific changes that are acceptable for each village.

Adolescent↗
PubMed2003

Availability of combination therapy for HIV: effects on sexual risk taking in a sample of high-risk gay and bisexual men.

The objective of this study was to assess the impact of successes in the medical treatment of HIV disease on the perceptions of high-risk gay and bisexual men attending an anonymous testing site towards becoming infected with HIV and on their decisions to have unsafe sex. A cross-sectional survey with a face-to-face interview and self-recorded information was used. A convenience sample of high-risk men seeking anonymous HIV antibody counselling was recruited for an intervention study. To be eligible, men had to have a history of at least one previous negative antibody test and unprotected anal intercourse within the last year. Upon enrollment, subjects were asked about the impact of new treatment developments on their decisions to engage in high-risk sex both in the recent past and in the future. In general, neither the recent successes in treating HIV nor the availability of combination therapy had any impact on the men's decisions about safe sex, although a minority of men reported less concern about becoming HIV-positive. Also, some men reported already having taken more risk. In conclusion, a small number of men in this high-risk population have increased risk behaviour as a result of recent treatment advances. These results merit continued monitoring.

Adult↗
PubMed2003

AIDS, HIV and STD among Japanese and Japanese-Americans in San Francisco, California, USA.

In affluent countries, some people may go abroad specifically for HIV testing or care for greater anonymity, better treatment, and less discrimination. A secondary analysis of data from the San Francisco Department of Public Health was conducted to characterize trends in AIDS incidence, AIDS care, sexually transmitted disease (STD) incidence, and HIV counselling and testing among Japanese in San Francisco. A total of 96 AIDS cases were diagnosed among ethnic Japanese, of whom 32 were born in Japan. From 1985 to 2000, 144 gonorrhoea and chlamydia cases were identified among Japanese. Of 368 self-identified Japanese seeking HIV counselling from 1995 to 1997, three (0.9%) were HIV-positive. The HIV/AIDS and STD epidemics among Japanese in San Francisco temporally parallels, but lags behind in magnitude, the epidemics for San Francisco's population as a whole. Some persons from Japan actively seek HIV/STD services while abroad. Our study points to several areas needing further research and improvements.

Acquired Immunodeficiency Syndrome↗
PubMed2001

Incidence of human immunodeficiency virus among male-to-female transgendered persons in San Francisco.

OBJECTIVE: To estimate HIV incidence among male-to-female transgendered persons (MtF transgendered persons) who repeatedly tested for HIV antibodies at public San Francisco counseling and testing sites between July 1997 and June 2000. METHODS: HIV seroconversions were identified and person-time of observation were estimated using the date and result of the current test and the self-reported date and result of the previous test. Factors independently associated with HIV seroconversion were determined using multivariable proportional hazard analysis. RESULTS: HIV incidence was 7.8 per 100 person-years (95% confidence intervals [CI], 4.6-12.3) based on 13 seroconversions among 155 repeat testers with 167.7 person-years of observation. African-American race/ethnicity (adjusted relative hazard ratio [HR], 5.0; 95% CI, 1.5-16.2) and unprotected receptive anal intercourse (HR, 3.9; 95% CI, 1.2-13.1) were independent predictors of HIV seroconversion. CONCLUSIONS: HIV is currently spreading at an extremely high rate among MtF transgendered persons in San Francisco, especially those who are African Americans.

Adult↗
PubMed2001

HIV incidence among repeat HIV testers at a county hospital, San Francisco, California, USA.

OBJECTIVES: To estimate HIV incidence, characterize correlates of HIV seroconversion, and monitor temporal trends in HIV transmission among patients repeatedly tested for HIV by a county hospital in San Francisco. DESIGN: Retrospective longitudinal study. METHODS: HIV incidence was retrospectively calculated among persons voluntarily tested for HIV antibody more than once at San Francisco's county hospital or one of its affiliated satellite community clinics between 1993 and 1999. Linkage of HIV test results in computerized databases identified "seroconverters" as individuals who had a negative antibody test followed by a positive test. The interval between tests was used as the person-time at risk. Cox proportional hazards analysis identified correlates of HIV seroconversion. RESULTS: A total of 84 HIV seroconversions were identified among 2893 eligible patients repeatedly tested for HIV antibody over a cumulative 5860 person-years (PYs) (incidence of 1.4 per 100 PYs, 95% confidence interval [CI]: 1.2-1.7). The majority of seroconversions (71 [84.5%]) were among injection drug users (IDUs) (incidence of 2.0 per 100 PYs, CI: 1.6-2.4). HIV incidence was highest among men who have sex with men (MSM) who were also IDUs (incidence of 3.8 per 100 PYs, CI: 2.7-5.1) and lowest among non-IDUs, heterosexual men, and non-IDU women (incidence of 0.3 per 100 PYs, CI: 0.1-0.6). In multivariate analysis, correlates of HIV seroconversion were age 25 to 29 years (hazard ratio [HR] = 3.9, CI: 2.4-6.3), MSM (HR = 2.9, CI: 1.9-4.4), and IDU (HR = 3.2, CI: 1.8-5.8). Overall, no temporal trend in annual HIV incidence was noted during the study period; however, HIV incidence among MSM IDUs increased from 2.9 per 100 PYs in 1996 to 4.7 per 100 PYs in 1998. CONCLUSIONS: The rate of seroconversion in this hospital and affiliated clinic population is unexpectedly high. Moreover, HIV transmission among IDU patients has not decreased over the last several years. The San Francisco county hospital provides a high-risk sentinel population to monitor emerging trends in HIV transmission, especially among IDUs, and presents multiple opportunities for prevention interventions, because these patients are being seen repeatedly by clinicians.

AIDS Serodiagnosis↗
PubMed2001

Cruising on the Internet highway.

This study evaluated differences in sexual behavior and risk for sexually transmitted diseases (STDs) among men who have sex with men (MSM) who met their partners on-line and those who did not. A self-administered questionnaire on sexual behavior was offered to a convenience sample of patients seeking public STD services. Thirty-two percent of MSM patients reported meeting a sexual partner over the Internet in the past year. MSM with on-line partners were younger, more likely to report sex with an HIV-positive person in the last year, and more likely to report casual partners in the last year compared with MSM with only off-line partners. HIV-negative MSM with on-line partners were more likely than HIV-negative MSM with only off-line partners to have received money or drugs for sex in the past year and to report sex with an HIV-positive partner in the past year. Although meeting partners on the Internet was common and associated with increased risk for STDs in MSM, it also presents new untapped opportunities for on-line health promotion and disease prevention.

Adult↗
PubMed2001

Differences in the temporal trends of HIV seroincidence and seroprevalence among sexually transmitted disease clinic patients, 1989-1998: application of the serologic testing algorithm for recent HIV seroconversion.

The authors compared temporal trends in the prevalence and incidence of human immunodeficiency virus (HIV) infection based upon 34,866 specimens from patients who attended the San Francisco, California, municipal sexually transmitted disease clinic between 1989 and 1998. HIV infection data were collected during annual blinded HIV serologic surveys. Incidence was determined by applying a serologic testing algorithm for recent HIV seroconversion that uses both a sensitive and a less sensitive enzyme immunoassay to stored HIV positive sera. The HIV seroprevalence declined from 15.2% in 1989 to 7.2% in 1998 (odds ratio per year = 0.92, 95% confidence interval (CI): 0.91, 0.94). Among homosexual men, the HIV prevalence declined from 50.9% in 1989 to 19.9% in 1998 (odds ratio per year = 0.86, 95% CI: 0.85, 0.88). The pooled seroincidence was 1.6% and did not change significantly over time (odds ratio per year = 1.0, 95% CI: 0.98, 1.1). The pooled seroincidence among homosexual men was 6.6% per year and remained steady between 1989 and 1998 (odds ratio per year = 0.99, 95% CI: 0.92, 1.1). During a dramatic, 10-year decline in seroprevalence of HIV infection, the incidence of HIV infection remained remarkably stable.

Adult↗
PubMed2001

Knock-knock: a population-based survey of risk behavior, health care access, and Chlamydia trachomatis infection among low-income women in the San Francisco Bay area.

To estimate the prevalence of urogenital chlamydial infection among young, low-income women in northern California and to describe correlates of infection, a population-based door-to-door household cluster survey was conducted from 1996 through 1998. The participants included 1439 women 18-29 years of age, with a mean age of 24 years, most of whom were African American (43%) or Latina (23%) and had a median income of $500-$999 per month. Most (94%) had received health care in the past year, and approximately 50% was covered by state insurance programs. Although more than half (62%) had had a recent pelvic examination, only 42% had recently used a condom with a new partner. The prevalence of urogenital chlamydial infection was 3.2% (95% confidence interval, 2.2%-4.2%). Women with chlamydia were more likely to be younger (18-21 years of age) and nonwhite and to have lower socioeconomic status. These data demonstrated an approximately 2-3-fold greater burden of infection than routine surveillance data have suggested.

Adolescent↗
PubMed2001

HIV surveillance among men who have sex with men.

OBJECTIVES: To review current approaches to HIV surveillance among men who have sex with men (MSM), identify illustrative best practices and lessons learned, and outline ways to enhance surveillance systems. METHODS: Review of the literature and institutional guidelines for HIV/AIDS, sexually transmitted infection (STI), and behavioral surveillance and summary of results of an international workshop. RESULTS: On-going formative research, HIV/AIDS and STI case reporting, HIV prevalence and incidence studies, and behavioral surveys are essential components of an effective HIV surveillance system for MSM. Alliances with key organizations and actors in MSM communities provide points of access, assist in the development of measures, and guide appropriate use of data. Sampling techniques (convenience, snowball, quota, microsite, time-location, and population-based) offering a range of methods, complexity, and cost have been successfully implemented in MSM communities. Plausible estimates of the size of MSM populations, which are ultimately crucial to the interpretation of surveillance data, can be improved upon using primary and secondary data. CONCLUSIONS: The purpose of HIV surveillance among MSM is not only to monitor disease occurrence and its antecedents, but to regularly use data to plan and evaluate prevention and care programs, advocate for prevention resources, and improve the health, social welfare and human rights of MSM. Practical, incremental steps can be taken to improve HIV surveillance among MSM in all regions of the world in all stages of the epidemic.

Cluster Analysis↗
PubMed2001

Two decades after vaccine license: hepatitis B immunization and infection among young men who have sex with men.

OBJECTIVES: This study investigated hepatitis B immunization coverage and the extent of hepatitis B virus (HBV) infection among young men who have sex with men (MSM), a group for whom hepatitis B vaccine has been recommended since 1982. METHODS: We analyzed data from 3432 MSM, aged 15 to 22 years, randomly sampled at 194 gay-identified venues in 7 US metropolitan areas from 1994 through 1998. Participants were interviewed, counseled, and tested for serologic markers of HBV infection. RESULTS: Immunization coverage was 9% and the prevalence of markers of HBV infection was 11%. HBV infection ranged from 2% among 15-year-olds to 17% among 22-year-olds. Among participants susceptible to HBV infection, 96% used a regular source of health care or accessed the health care system for HIV or sexually transmitted disease testing. CONCLUSIONS: Despite the availability of an effective vaccine for nearly 2 decades, our findings suggest that few adolescent and young adult MSM in the United States are vaccinated against hepatitis B. Health care providers should intensify their efforts to identify and vaccinate young MSM who are susceptible to HBV.

Adolescent↗
PubMed2000

Surveillance for incident HIV infection: new technology and new opportunities.

Although surveillance for HIV infection has traditionally focused on the incidence of AIDS and the prevalence of HIV, new diagnostic technologies that allow the estimation of incident HIV infection have become available. Number and distribution of new cases of HIV infection, rather than old cases, are the data most relevant to guide rational application of HIV prevention programs. Historically, incident HIV infection has been measured in longitudinal cohort studies, diagnosed clinically or since 1993 by detection of seroconverting patients (during the window period before appearance of HIV antibody) who are viremic as measured by p24 antigen or RNA-PCR. The sensitive-less sensitive EIA test (or serologic testing algorithm for recent HIV seroconversion [STAHRS]) has now made the serologic diagnosis of incident HIV infection in individual patients as well as the estimation of HIV incidence in populations possible. Examples of the public health application of this are studies of HIV incidence in anonymous test site attendees, sexually transmitted disease clinic patients, and in-treatment injection drug users in San Francisco. These sorts of studies allow us not only to measure incidence cross-sectionally but also facilitate surveillance for HIV subtypes and primary antiretroviral resistance, targeting early antiretroviral therapy and partner notification, and understanding who is "failing" prevention. Having an HIV surveillance system that focuses on incident rather than prevalent infection should be our long-term goal.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Evaluating national HIV prevention indicators: a case study in San Francisco.

OBJECTIVES: To field-test the availability, interpretability, and programmatic usefulness of 37 proposed national HIV prevention indicators (HPI) intended to evaluate community-level impact of HIV prevention efforts in San Francisco. METHODS: HPI were defined for four populations (high risk heterosexuals, injecting drug users, men who have sex with men, and childbearing women) and for four domains (biological, behavioral, service, and socio-political). HPI were obtained from existing data sources only. Trends in HPI were examined from 1990 to 1997. RESULTS: Existing data provided 29 (78%) of the 37 proposed HPI; eight HPI were not available because California does not have HIV case reporting. Interpretation was limited for several HPI due to small sample size, inconsistencies in data collection, or lack of contextual information. Data providing behavioral HPI were scarce. HPI were consistent with historical patterns of HIV transmission in San Francisco but also highlighted new and worrisome trends. Notably, HPI identified recent increases in risk for HIV transmission among men who have sex with men. CONCLUSIONS: Despite limitations, the proposed national HPI provided evidence of the aggregate effectiveness of prevention efforts in San Francisco. Supplemental or local HPI are needed to fill data gaps, add context, and increase the scope and programmatic usefulness of the national HPI.

Centers for Disease Control and Prevention, U.S.↗